Correct Answer - Option 1 : 48 min
Given:
When walking at 3/4th of his usual speed time taken to reach office is 16 mins more
Concept used:
When the distance is constant, speed ∝ (1/time)
Calculation:
Let the usual speed be S.
New speed = S × (3/4)
⇒ The ratio of usual speed to new speed = 4 ∶ 3
⇒ The ratio of the usual time to new time = 3 ∶ 4
Let his usual time be 3x and the new time is 4x.
Difference in time = 4x - 3x = 16 mins
⇒ x = 16 mins
The usual time taken = 3x
⇒ 3 × 16 = 48 mins
∴ The usual time to reach the office is 48 mins.